ABSTRACT
ABSTRACT Introduction Instruments to manage adverse effects of endocrine therapy with Aromatase inhibitors (AI) may improve adherence and persistence to treatment and Health-Related Quality of Life (HRQL). The 31-item Cervantes Scale (CS-31) is an HRQL questionnaire with particularities of the perimenopausal and postmenopausal period that could be an appropriate instrument to assess HRQL in Breast Cancer (BC) survivors. Objective This study aimed to perform additional validation of the CS-31 for BC survivors undergoing adjuvant endocrine therapy. Methods This prospective study was performed at three time points named T0, T1, and T2: initial, intermediate, and final follow-up period, respectively, totaling 24 months of follow-up. At each time point, the participants completed the CS-31, Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F), and Hospital Anxiety and Depression Scale (HADS). The internal consistency, construct validity, responsiveness analyses, and known-group validity of CS-31 were evaluated. Results This study included 89 postmenopausal women diagnosed with hormone receptor-positive early BC in adjuvant endocrine therapy with AI. The internal consistency was good (Cronbach's alpha = 0.89). Construct validity received a positive rating, with 100% of results consistent with prior hypotheses. A prospective improvement in HRQL was identified for the CS-31 Global Score and FACIT-F Total Score and for most of their domains. Furthermore, women with anxiety and depression by HADS presented worse HRQL by CS-31. Conclusion The authors identified that the CS-31 seems to be appropriate for use in oncology medical routine and may help to monitor adverse effects and HRQL of BC survivors during adjuvant endocrine therapy.